Wear resistant shuttle spring



April 16, 1968 R. H. BOGGS WEAR RESISTANT SHUTTLE SPRING Filed Sept. 1, 1966 UNCOATED RIGID AREA UNcoATED FLEX AREA UNCOATED AREA PRoTEcTwE To THIS AREA PRIOR To CHRoME PLATING HARD CH ROME COATED AREA INVENTOR.

ROY H. Boses ATTORNE Y3.

COATING APPLIED United States Patent 0 3,378,044 WEAR RESISTANT SHUTTLE SPRING Roy H. Boggs, Timble Lake Road, Anderson, S.C. 29621 Filed Sept. 1, 1966, Ser. No. 576,579 1 Claim. (Cl. 139-207) ABSTRACT OF THE DISCLOSURE A shuttle spring having opposed grooved metal tips is provided with a layer of hard chrome from about .001 inch to about .010 inch in thickness coating the grooved tips. A rigid metallic shank portion and a flex portion are free of chrome.

This invention relates to loom shuttles, and more particularly to a wear resistant shuttle spring or strap.

Proper alignment of the bobbin within the ioom shuttle is recognized as being an important factor in the weaving Of cloth. In looms having an automatic change operation the shuttle spring is called upon to repeatedly receive full filling bobbins when the necessity for replacing spent bobbins arises. Due to the rather violent action of the bobbin change mechanism considerable wear occurs as a result of continued use particularly in the area of the grooved portions in the tips of the shuttie spring. In many weaving operations proper bobbin alignment in the shuttle is critical and often grips of standard type wear so that the groves allow the tip of the bobbin to drop out of proper alignment. Many times such dropping of the bobbin becomes excessive after only short periods of operation so that it becomes necessary to replace the grip just as it is beginning its useful life. Many attempts have been made to solve this problem including the addition of shims to raise the forward portion of the shuttle springs, but these attempts have proved only partially successful and posses inherent disadvantages. Other attempts included coating the straps as with chrome, but such attempts have met with failure because disadvantages exceeded the advantages produced by coating.

Chrome coating has formerly resulted in hydrogen embrittlernent of the metal of which the shuttle spring are made in the flex area of the spring. While it is possible to relieve hydrogen embittlernent by baking it at about 350 Fahrenheit for several hours, uniform results are from a practical standpoint impossible to predict or achieve. Then too, the baking cycle is expensive and does not justify the results achieved. After prolonged use flaking of the chrome coating results beginning in the flex area.

It has been found that coating the springs only in the tip area solves the above mentioned problems and results in a superior shuttle spring possessing improved durability and functional characteristics. It is with such coating and the resulting shuttle spring that the present invention is concerned.

Accordingly, it is an important object of the present invention to produce a shuttle spring having improved wear and functional characteristics.

Another important object of the inveniton is to provide a shuttle spring which is capable of maintaining proper bobbin alignment in the shuttle over extended periods of time.

Still another important object of the invention is to produce an improved shuttle spring which may be manufactured economically and which will function without replacement over extended periods of operation.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

3,378,044 Patented Apr. 16, 1968 The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing forming a part thereof, wherein an example of the invention is shown and wherein:

FIGURE 1 is a perspective view illustrating a shuttle spring constructed in accordance with the present invention, and

FIGURE '2 is an enlarged sectional plan view taken on the line 22 in FIGURE 1.

The drawing illustrates a wear resistant shuttle spring including a pair of opposed hard chrome coated grooved metallic tips A. The tips A are coated with a layer of hard chrome B from about .001 inch to about .010 inch in thickness. A rigid metallic U-shaped shank portion C has arms joined to free-ends of legs of the shank portion through an arcuate metallic flex portion D. The arms carry the tips A integrally therewith. The flex portion D is freed of chrome by covering same with a resist during application of the layer of hard chrome to the tips. The layer of hard chrome terminates short of the flex portion D of the shuttle spring. Thus, the grooved tips receive bobbin rings so as to avoid excessive wear of the tips as normally ocurs upon repeated bobbin change operations, and the layer of hard chrome remains without impairing the action of the hex portion.

Hydrogen embrittiement always occurs when metals are electrically plated with hard chrome. Hydrogen ions are absorbed by the metal during such a plating operation, thereby increasing the crystallinity of the subjected metal part. Attempts to relieve this condition and return the metal part to its original state of flexible endurance include heating the metal part to at least 350 F. for a period of time usually one to several hours, depending on the weight and physical configuration of the metal substrate. However, uniform results may not be obtained, and it has heretofore been impractical to electrically plate shuttle springs with hard chrome.

In accordance with the invention a standard currently available shuttle spring is first partially coated with any of the acid-resistant commercially available resist coatings, such as Unichrome 323 Red, which is supplied by the Metal and Thermid Division of Udylite Corporation, Detroit, Mich. Such a coating resists the plating of chrome in the flex areas of a loom shuttle spring, thereby subjecting only the spring grooved tips to be chrome plated. This method produces a shuttle spring with improved service life at these grooved tips while not detracting from the service life normally expected in the flex areas. Another such resist coating composition is outlined in detail in United States Patent No. 2,999,771.

The shuttle spring is then electrically plated with hard chrome until the chrome build-up amounts to about .001" to about .010" in thickness. Springs so produced have been found to have a useful life three times longer than untreated springs. After the springs of the present invention begin to show excessive wear they may be retreated in the grooved areas so that replacement of the springs is minimized, except for actual breakage or other faults that might occur.

The tips A have usual opposed grooves 10 and a guide surface 11 is provided to assist the bobbin into position wherein the rings on the butt of the bobbin are received within the grooves 10. As illustrated, the hard chrome B covers the entire tip portion A being received within the grooves 10 and extending into the arm portion 12 which is integral with the uncoated flex portion or area D. The flex portion includes an arcuate outwardly curving portion 13 integral with the arm 12 and an inwardly curving arcuate portion 14 which is integral with the 0 legs 15 of the shank C. The horizontal transverse bore 16 is provided to accommodate the usual cross-bolt (not form the uncoated rigid portion or area in the shank portion of the shuttle spring.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claim.

What is claimed is:

1. A Wear resistant shuttle spring including, a pair of opposed grooved metallic tips for receiving a full filling bobbin on a change operation, a layer of hard chrome from about .001 inch to about .010 inch in thickness coating said grooved tips, a rigid metallic U-shaped shank portion with arms joined to free-ends of legs of the shank portion through an arcuate metallic flex portion, said arms carrying said tips integrally therewith, said flex portion being freed of chrome by covering same with a 'minating short of the flex portion of theshuttle spring,

whereby said grooved tips thus coated with the layer of hard chrome receive bobbin rings avoiding excessive wear of the tips as normally occurs upon repeated bobbin change operations, and whereby the layer of hard chrome remains without impairing the action of the flex portion.

References Cited UNITED sTATEs PATENTS 1,074,908 10/1913 Stimpson 139 2o7 2,364,740 12/1944 Menking 139196 2,596,651 5/1952 Carter 139 1s3 3,259,150 7/1966 Gustafson 139-20 7 FOREIGN PATENTS 461,371 10/1913 France.

650,703 9/1928 France.

resist coating during application of the layer of hard 20 ROBERT MACKEY Acting Primary Examiner chrome to the tips, and said layer of hard chrome ter- I. KEE CHI, Assistant Examiner. 

